# Hygrometer salt test - varying results.



## akaAtomix (May 28, 2013)

I am working on my coolidor and just got a Accurite Hygrometer. I did a salt test by eyeballing salt and water in a water cap. The humidity after 36 hours was 77%. I did an additional test using 1 tablespoon of salt and 1 teaspoon of water, and the humidity is 81%.

I am not quite sure which reading to go with, or maybe do one more? I used distilled water, table salt, and a mason jar.


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## divedoc (Mar 7, 2013)

You want to make a *very* thick slurry of salt. It actually shouldn't look "wet," but more like crusty salt.

Many people here will tell you that the salt test is inaccurate. Technically, there's nothing inaccurate about the science behind the test, and if done properly you will get 75% RH every time. The tough part is getting the slurry right -- if you add too much water, you get closer and closer to basically having a cup of water in there, and if you don't add enough, you get closer to having a pile of dry salt.

This is why a lot of people will push you towards things like Boveda packs for calibration, and that's good advice. However, I can tell you that I used the salt test to calibrate my hygrometer, and when I later purchased a Boveda pack for other purposes, I was off by 1-2%. Is that worth the $4 for a Boveda pack? It was to me, since I was being impatient and I didn't want to wait for shipping. But I don't think anyone's wasting money by going the other way; it's very convenient and accurate.


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